Cream butter with vanilla extract until light and fluffy.
Add sugar, creaming well.
Mix in flour and salt, then pecans.
Shape dough into 1 inch balls and flatten slightly.
Place on ungreased cookie sheets.
Bake at 350Â°F 25 to 30 minutes, or until lightly browned.
Remove from cookie sheets and cool slightly.
Roll in confectioners' sugar.